The present invention relates to a stringing tool for rackets such as the rackets used for playing tennis, squash, badminton and like games.
Tennis rackets, and the like, as is well known, are structurally made of a generally oval frame, made of laminated wood, metal, or composite materials such as glass or carbon fibers provided with an integral handle or grip. The open area within the frame is covered with a plurality of interlacing "horizontal" and "vertical" criss-crossing strings, regularly spaced and running from one side of the frame to the opposite side and from the bottom of the frame, provided with the handle, to the top of the frame. The strings generally consist of a single length, or of two lengths of a string made of, for example, sheep gut, or nylon. Each length of string is laced through appropriate apertures, or stringing holes, through the periphery of the frame between the open area of the frame and the peripheral surface of the frame. During the manufacture of the racket, or when the racket is restrung, one end of the string is provided with a knot which forms an anchoring means for the end of the string in the frame start stringing hole, and after the full length of string has been laced through the stringing holes to form a net-like arrangement disposed within the frame, tension is applied by way of an appropriate tensioning device for tensioning the whole length of string, and consequently each individual string with an appropriate tensioning force, for example 55 to 60 lbs. for tennis racket, 35 to 45 lbs. for squash rackets, and 25 to 30 lbs. for badminton rackets. The free end of each length of string is then appropriately tied.
Such a structure, and the method for stringing rackets, present many inconveniences. When using one or two lengths of string, each length of string must be laced alternatively above and below each of the already installed string portions, and laced in a regular pattern through the stringing holes in the frame, doubled back and laced through an adjacent stringing hole in the frame, and returned to the other side of the frame, once again passing over and under the already installed perpendicular string portions. If one of the individual string portions breaks during use, the whole racket has to be restrung, when a single length of string is used, as no means are provided for anchoring each individual string section in the stringing holes.
In addition, stringing machines are complex and costly, and restringing requires that stringing machines be used in order to do the job efficiently. Some of the disadvantages and shortcomings of the prior art racket stringing arrangements and methods have been remedied by providing individual string lengths and frame anchoring means for each horizontal and vertical string of a racket, as disclosed for example in U.S. Pat. Nos. 3,994,495, 4,140,316, 4,309,033, British Pat. Specification No. 2,071,253 and co-pending application Ser. No. 297,851, for example.